Additively manufactured Y2O3-reinforced high speed steel with excellent strength and wear resistance

• Oxide-strengthened M2 high-speed steels with different contents were prepared using the LPBF process and it was found that the oxide-added M2 high-speed steels had a high density of L12 precipitates, and these L12 precipitates significantly improved the wear resistance and strength of the materials. • The addition of oxides induces the generation of an oxide film on the material during friction, lowering the coefficient of friction and reducing the wear volume. The wear volume of the sample with 1 % Y2O3 addition decreased by about 50 % compared to pure M2 HSS. • Through intensive collaboration with additive equipment manufacturers, we have applied the material and machining parameters to the fabrication of advanced tools and have conducted milling studies. Below is a sample of our independently designed and prepared milling cutter with shape-following cooling, which has good molding accuracy and cutting performance. Materials enhanced with nanoparticles and prepared through Laser Powder Bed Fusion (LPBF) exhibit significantly improved wear resistance and ductility. Nonetheless, there is a current lack of research on the microstructural characteristics and wear mechanisms of particle-reinforced high-carbon steels produced via LPBF. In this study, we systematically investigate the microstructure of M2 high-speed steel with varying Y2O3 nanoparticle contents and its behavior under high-load reciprocating friction at room temperature. Special attention is given to the microstructural evolution caused by wear and the influence of Y2O3 nanoparticles on the steel’s microstructure. When 1% Y2O3 is added, the wear rate of the alloy at room temperature decreases by approximately 50% compared to the base alloy. TEM analysis reveals that Y2O3 nanoparticles induce the formation of a high-density L1 2 coherent precipitate phase in M2 high-speed steel, leading to the development of a thicker oxide layer during wear. The exceptional wear resistance of the alloy containing 1 % Y2O3 at room temperature is primarily due to the precipitation strengthening from the dense coherent L1 2 phase and the lubricating effect of the oxide layer formed near the sliding surface. This work provides crucial insights into the development of high-performance tool materials and the mechanisms enhancing their wear resistance.